Near Green River in Emery County, Utah — The American Mountains (Southwest)

Spotted Wolf Canyon

Photographed by Tom Bosse, June 7, 2025

1. Spotted Wolf Canyon Marker

Inscription. They call it the San Rafael Reef, a 30-mile-long stone barrier, a sawtooth ridge at the eastern edge of nowhere. For centuries, only the most intrepid travelers found their way through its narrow slot canyons and on to the Green River crossing. The early Spanish explorers detoured 20 miles north to avoid the forbidding wall. In 1883 the Denver and Rio Grand Railroad also avoided breaching the Reef, laying track just east of its sheer walls, north to Salt Lake City. In 1957 the decision was made to increase the nation’s interstate highway system and I-70 was engineered to bisect the San Rafael Swell. Here, at Spotted Wolf Canyon, workers could stand and touch both walls of the canyon before construction began in October 1967. Engineers and surveyors used body harnesses and ropes to work as high as 400 feet above the canyon floor. Crews excavated 3.5 million cubic yards of rock from the area at a cost of $4.5 million for eight miles of road. On November 5, 1970, the Utah Department of Transportation opened the 70-mile section from Fremont Junction to Green River for two-lane traffic. Two more lanes were added in the mid-1980s.

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Excavation begins through the Reef. Courtesy: Emery County Sheriff’s Department.

[Caption]: Surveying in the bottom of Spotted Wolf Canyon. Courtesy: Emery County Sheriff’s Department.

Topics. This historical marker is listed in these topic lists: Natural Features • Roads & Vehicles. A significant historical month for this entry is October 1967.

Location. 38° 56.025′ N, 110° 28.347′ W. Marker is near Green River, Utah, in Emery County. It can be reached from Interstate 70, on the right when traveling east. Marker located at the Spotted Wolf Canyon View Area. Touch for map. Marker is in this post office area: Green River UT 84525, United States of America. Touch for directions.

Regionally, this marker is in Canyon Country.

It is also in the American Mountain West,

on the Colorado Plateau,

and at the Four Corners.

Globally, it is in North America,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Historically, it finds itself in what was once New Spain

and also Mexico’s Alta California.

Other nearby markers. At least 2 other markers are within walking distance of this marker: Crossing the River (within shouting

Photographed by Tom Bosse, June 7, 2025

2. Spotted Wolf Canyon Marker

Marker is on the left.

distance of this marker); The San Rafael Swell (approx. 0.7 miles away).

Related markers. Click here for a list of markers that are related to this marker.

Spotted Wolf Canyon image. Click for full size.

Photographed by Tom Bosse, June 7, 2025

3. Spotted Wolf Canyon

Credits. This page was last revised on August 24, 2025. It was originally submitted on August 24, 2025, by Tom Bosse of Jefferson City, Tennessee. This page has been viewed 267 times since then and 141 times this year. Photos: 1, 2, 3. submitted on August 24, 2025, by Tom Bosse of Jefferson City, Tennessee. • Andrew Ruppenstein was the editor who published this page.